Best practice for code modification during ant build

Admitted, this doesn't sound like a best practice altogether, but let me explain. During the build, we need to paste the build number and the system version into a class whose sole purpose is to contain these values and make them accessible.

Our first idea was to use system properties, but due to the volatility of the deployment environment (an other way of saying "the sysadmins are doing weird unholy creepy things") we would like to have them hard-coded.

Essentially I see 4 possibilities to achieve it in ant :

use

<replace>

on a token in the class

The problem with this approach is that the file is changed, so you have to replace the token back after compilation with a

I think a simpler approach would be to have your Version.java class read from a simple .properties file included in the JAR, and just generate this .properties file at build-time in the Ant build. For example just generate: